Elevator



April 15 1924.

N. O. LINDSTROM ET AL ELEVATOR 3' Sheets-Sheat 1 Filed March 17. 923

v INVENTORS /V/L$ 0- Z/NDS'TFO BY X TORNEYS Ajnil 15 1924..

o. LINDSTROM ET AL ELEVATOR Filed March 17. 1923 I5 Sheets-Sheet 5 IN VENTORS /V/ 5 0. U/VDSTROM Cflil. FE. OLOFSD/V ATTORNEYS Patented Apr. 15, 1924..

Ui iii :1 BE STATES FATENT @FHQFQZ.

NILS O. LINDSTROIVI, OF NUTLEY, AND CARL F. E. OLGFSON, E WEST ORANGE, NEW JERSEY, ASSIGNORS TO ALO'NZO B. SEE, OF BROOKLYN, NEW YORK.

ELEVATOR.

Application filed March 17, 1923. Serial No. 625,707.

To all whom it may concern:

Be it known that we, NILs O. LINDSTROM and CARL F. E. OLOFSON, citizens of the United States, residing at Nutley, county of Essex, State of New Jersey, and WVest Orange, county of Essex, and State of New Jersey, respectively, have invented certain new and useful Improvements in Elevators,

of which the following is a full, clear, and

exact description.

In elevators, hoisting devices, and the like, Where gearing is utilized between the driving motor and the cable sheave in order to make possible the use of high speed driving motors, it is necessary to have some backlash, clearance, or lost motion in the meshing gearing if undue binding or friction is to be avoided. This backlash, lost motion or clearance between the teeth of the driving or driven gears is, however, objeotionable because-in starting and stopping of the elevator, noises, and jolts and shocks to the car result therefrom, which are particularly annoying in passenger elevators.

An object of the invention is to provide improved operating mechanism for elevators and the like, in which high speed driving motors may be utilized without the objectionable effects of the back-lash; with which the wear on the operating parts is lessened; with which the safety factor of the elevator is increased, which operates smoothly and noiselessly, and which is simple and relatively inexpensive. Other objects and advantages will be apparent from the following description of an embodiment of the invention, and the novel features will be particularly pointed out hereinafter in claim.

In the accompanying drawing:

Fig. 1 is a sectional elevation of a driving unit for an elevator, which is constructed in accordance with our invention;

Fig. 2'is a sectional elevation through the same taken substantially along the line 22 of Figure 1;

Fig. 3 is a transverse section of the same taken substantially along the line 33 of Figure 1; and i a is an elevation, partly in section,

of an elevator shaftway and elevator which may utilize a driving unit constructed in accordance with the invent-ion.

In the illustrated embodiment of the invention, an elevator car or cage 1 is adapted to travel vertically in a she. tway 2, be ing supported and operated by cables 3 wlnchpass over a sheave 4 mounted at one end of the shaftway. The cables 3 after passing over the sheave may be connected to a counter weight 5, and the latter by a cable 6 which passes around a pulley 7 at the opposite end of the shaftway from the sheave i may be connected tothe car or cage 1. This type of elevator is not apart of the present invention, but is described briefly in order that the improved driving unit forming the subject of the present invention may be explained in a practical application.

The sheave i, is mounted on av shaft 8, and a worm wheel 9 also mounted on the shaft 8 is connected for rotation with the she-ave 4.. The shaft 8 is supported in a frame 10 which may comprise the frame of the improved driving unit, and this frame is supported in the shaftway in any suitable manner such as by I-beams 11. A pair of driving shafts 12 and 13 are rotatably mounted in the frame 10, such as at diametrically opposite sides of the worm wheel 9, so as to extend substantially tangentially of the worm wheel. Each driving shaft carries a worm screw 14 which meshes with the worm wheel for driving the same. v The armature 15 of an electric motor is disposed in alignment with and directly connected to the upper end of the shaft 12 for rotating the same when the electric motor is operated. The armature 16 of a similar electric motor is disposed in align ment with and directly connected to a shaft 13 for driving the same. Each shaft 12 and 13 is provided at its lower end with a double thrust bearing 1'7, with suitable ball or roller bearings, for taking up the end thrusts in both directions upon the shafts 12 and 13, and for preventing endwise displacement of these shafts. Guides or bearings 18 may be provided around the shafts 12 and 13 adjacent their upper ends for assisting in holding the shafts in align- 'ment while permitting their rotation.

The shafts of the armatures 15 and 16 are provided with brake drums 19. Brake levers 20 are disposed on opposite sides of each of the brake drums, and are mounted for rocking movement on pivots 21 carried by the frame 10. Brake shoes 22 are articuf lately connected by pivots 23 to the ends f? of sectional cores 26 are mounted at opposite ends in the solenoid 24, so that when the solenoid is energized the sectional cores will be drawn toward one another and into the solenoid. The brake levers 20 upon each of the corresponding sides of the brake drums 19 extend toward one another and over one of the sectional cores of the solenoid, and each lever is connected by a bolt 27 to the core section 26 which it overlies. The bolts 2? pass freely through apertures 28 in the brake levers, and nuts 29 are adjustable on the bolts 27 so as to provide for an adjustment of the brake levers'toward or from the ends of the solenoid. Springs 30 act between abutments 31 on the frame and each of the'brake levers 20, so as to normally urge the brake levers in directions to cause an application of the brake shoes 22 to the brake drums 19 and check rotation of the latter. The energization of the solenoid tends to pull the core sections 26 inwardly into the solenoid and operate the brake levers against the action of the springs 30 in directions which carry the brake shoes out of frictional engagement with the brake drums. V

The frame may comprise a base part 10 and an upper shell-like casing 1O which is secured upon the base section 10 and which is in the nature of a casing for surrounding and protecting the motors and gearing.

The motors are connected for simultaneous operation in a direction such that they both act through their worm screws 1a to drive the worm wheel 9 in common in either direction. Because of the simultaneous driving action of the worm screws 1 1 upon the worm wheel, the driving force exerted upon the teeth of the worm wheel 9 will be 'VVhen the power of the motor is cut ofi the solenoid 2a is also de-energized, whereupon the springs 30 became active and operate the brake levers 20 to cause an applicationof the brake shoes 22 to the brake drums 19. This checks the rotation of the driving shafts 12 and 13 and serves to hold the driving shafts and through them the worm wheel and sheave in the position in which they are stopped. When the driving motors are again started the solenoid 2 will be energized simultaneously, which acts to release the brakes from the brake drums.

hen the power to operate the motors is out OK, the armatures of the motors will practically never continue to rotate by inertia through exactly the same extent, and

since the brakes always have a more or less. unequal actlon, one worm screw always will slightly lead the other in stopping, so that the worm wheel will be clamped firmly between them with no backlash or lost motion. When the motors are started they practically never start exactly simultaneously, even though they are as nearly identical as it. is possible to make them, and the brakes will not always release the driving shafts exactly simultaneously. The result is that one worm screw will always slightly lead the other in starting, so that the lost motion or backlash will in effect be eliminated, and the worm wheel with the pulley sheave which is connected thereto, will be driven positively without lost motion in the driving connection.

With the worm gear connection between the motors and the worm wheel, the desired reduction in speed may be readily accomplished in a simple manner, and high speed motors may be employed with satisfactory results. It will, therefore, be obvious that with the separate double gear drive on the worm wheel from independent sources of power, the objectional features of gear drives are eliminated, and a smoothly running operating mechanism is obtained regardless of the direction of the drive of the worm wheel. The two brakes, one for each motor, also providea safety feature in that in case of slippage of one, the other will hold the worm wheel and cable sheaves against rotation. A

It will be understood that the shafts 12 and 13 may be disposed in different relative positions, around the worm wheel. For example, one of the shafts could be placed in a horizontal position, and the other in a vertical position, or both could be placed in a horizontal position while meshing with the worm wheel. It will also be understood that various changes in the details and arrangements of parts which have been herein described and illustrated for the purpose oi explaining the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as with th expressed in the appended claim.

We claim: In elevators, hoisting devices, and the like,

5 a cable sheave, a Worm gear Wheel connected to the sheave for driving the same, a plurality of separate Worm screws meshing e Worm Wheel, and a separate operatlng motor for each Worm screw.

In Witness whereof, We hereunto subscribe 1 our signatures.

NILS O. LINDSTROM. CARL F. E. OLOFSON. 

